Commit 3dd84782 authored by Artem Bityutskiy's avatar Artem Bityutskiy Committed by Al Viro
Browse files

affs: get rid of affs_sync_super 



This patch makes affs stop using the VFS '->write_super()' method along with
the 's_dirt' superblock flag, because they are on their way out.

The whole "superblock write-out" VFS infrastructure is served by the
'sync_supers()' kernel thread, which wakes up every 5 (by default) seconds and
writes out all dirty superblocks using the '->write_super()' call-back.  But the
problem with this thread is that it wastes power by waking up the system every
5 seconds, even if there are no diry superblocks, or there are no client
file-systems which would need this (e.g., btrfs does not use
'->write_super()'). So we want to kill it completely and thus, we need to make
file-systems to stop using the '->write_super()' VFS service, and then remove
it together with the kernel thread.

Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent a215fef7

fs/affs/affs.h

+6 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#include <linux/buffer_head.h>

#include <linux/amigaffs.h>

#include <linux/mutex.h>

#include <linux/workqueue.h>



/* AmigaOS allows file names with up to 30 characters length.

 * Names longer than that will be silently truncated. If you
@@ -101,6 +102,9 @@ struct affs_sb_info { 
	char s_volume[32];		/* Volume prefix for absolute symlinks. */

	spinlock_t symlink_lock;	/* protects the previous two */

	struct super_block *sb;		/* the VFS superblock object */

	int work_queued;		/* non-zero delayed work is queued */

	struct delayed_work sb_work;	/* superblock flush delayed work */

	spinlock_t work_lock;		/* protects sb_work and work_queued */

};



#define SF_INTL		0x0001		/* International filesystem. */
@@ -121,6 +125,8 @@ static inline struct affs_sb_info *AFFS_SB(struct super_block *sb) 
	return sb->s_fs_info;

}



void affs_mark_sb_dirty(struct super_block *sb);



/* amigaffs.c */



extern int	affs_insert_hash(struct inode *inode, struct buffer_head *bh);

fs/affs/bitmap.c

+2 −2
Original line number Diff line number Diff line
@@ -103,7 +103,7 @@ affs_free_block(struct super_block *sb, u32 block) 
	*(__be32 *)bh->b_data = cpu_to_be32(tmp - mask);



	mark_buffer_dirty(bh);

	sb->s_dirt = 1;

	affs_mark_sb_dirty(sb);

	bm->bm_free++;



	mutex_unlock(&sbi->s_bmlock);
@@ -248,7 +248,7 @@ find_bit: 
	*(__be32 *)bh->b_data = cpu_to_be32(tmp + mask);



	mark_buffer_dirty(bh);

	sb->s_dirt = 1;

	affs_mark_sb_dirty(sb);



	mutex_unlock(&sbi->s_bmlock);

fs/affs/super.c

+37 −11
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include <linux/magic.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/writeback.h>

#include "affs.h"



extern struct timezone sys_tz;
@@ -47,6 +48,7 @@ affs_put_super(struct super_block *sb) 
	struct affs_sb_info *sbi = AFFS_SB(sb);

	pr_debug("AFFS: put_super()\n");



	cancel_delayed_work_sync(&sbi->sb_work);

	kfree(sbi->s_prefix);

	affs_free_bitmap(sb);

	affs_brelse(sbi->s_root_bh);
@@ -54,23 +56,45 @@ affs_put_super(struct super_block *sb) 
	sb->s_fs_info = NULL;

}



static void

affs_write_super(struct super_block *sb)

{

	if (!(sb->s_flags & MS_RDONLY))

		affs_commit_super(sb, 1);

	sb->s_dirt = 0;

	pr_debug("AFFS: write_super() at %lu, clean=2\n", get_seconds());

}



static int

affs_sync_fs(struct super_block *sb, int wait)

{

	affs_commit_super(sb, wait);

	sb->s_dirt = 0;

	return 0;

}



static void flush_superblock(struct work_struct *work)

{

	struct affs_sb_info *sbi;

	struct super_block *sb;



	sbi = container_of(work, struct affs_sb_info, sb_work.work);

	sb = sbi->sb;



	spin_lock(&sbi->work_lock);

	sbi->work_queued = 0;

	spin_unlock(&sbi->work_lock);



	affs_commit_super(sb, 1);

}



void affs_mark_sb_dirty(struct super_block *sb)

{

	struct affs_sb_info *sbi = AFFS_SB(sb);

	unsigned long delay;



	if (sb->s_flags & MS_RDONLY)

	       return;



	spin_lock(&sbi->work_lock);

	if (!sbi->work_queued) {

	       delay = msecs_to_jiffies(dirty_writeback_interval * 10);

	       queue_delayed_work(system_long_wq, &sbi->sb_work, delay);

	       sbi->work_queued = 1;

	}

	spin_unlock(&sbi->work_lock);

}



static struct kmem_cache * affs_inode_cachep;



static struct inode *affs_alloc_inode(struct super_block *sb)
@@ -132,7 +156,6 @@ static const struct super_operations affs_sops = { 
	.write_inode	= affs_write_inode,

	.evict_inode	= affs_evict_inode,

	.put_super	= affs_put_super,

	.write_super	= affs_write_super,

	.sync_fs	= affs_sync_fs,

	.statfs		= affs_statfs,

	.remount_fs	= affs_remount,
@@ -302,6 +325,8 @@ static int affs_fill_super(struct super_block *sb, void *data, int silent) 
	sbi->sb = sb;

	mutex_init(&sbi->s_bmlock);

	spin_lock_init(&sbi->symlink_lock);

	spin_lock_init(&sbi->work_lock);

	INIT_DELAYED_WORK(&sbi->sb_work, flush_superblock);



	if (!parse_options(data,&uid,&gid,&i,&reserved,&root_block,

				&blocksize,&sbi->s_prefix,
@@ -526,6 +551,7 @@ affs_remount(struct super_block *sb, int *flags, char *data) 
		return -EINVAL;

	}



	flush_delayed_work_sync(&sbi->sb_work);

	replace_mount_options(sb, new_opts);



	sbi->s_flags = mount_flags;

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